void do_tests()
{
	string str;

	ASSERT(
	catch(clear_bit("", 1000000000000)));
	ASSERT(
	catch(clear_bit("", -2)));

	str = "11111";
	str = clear_bit(str, 7);
	ASSERT(!test_bit(str, 7));
	str = clear_bit(set_bit(str, 12), 12);
	ASSERT(!test_bit(str, 7));

	ASSERT(str == clear_bit(str, 40));
}

